goldfinch vs New World goldfinch

goldfinch and New World goldfinch both are nouns.

Word	Noun	Adjective	Verb	Adverb
goldfinch	Yes	No	No	No
New World goldfinch	Yes	No	No	No

As nouns, goldfinch and New World goldfinch are synonyms defined as:

goldfinch and New World goldfinch: American finch whose male has yellow body plumage in summer

Other synonyms of goldfinch include Spinus tristis, yellowbird.

goldfinch (noun)	New World goldfinch (noun)
small European finch having a crimson face and yellow-and-black wings	American finch whose male has yellow body plumage in summer
American finch whose male has yellow body plumage in summer